<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style>
#div1 {width:200px; height:200px; background:red;}
</style>
<script>
	window.onload=function(){
		var oDiv=document.getElementById('div1');
		if(oDiv.currentStyle){
			//IE
			alert(oDiv.currentStyle.width);
		}
		else{
			//火狐等
			alert(getComputedStyle(oDiv,null).width);
		}
	};
</script>
</head>

<body>
<div id="div1">
</div>
</body>
</html>
